Retractable Y-shaped foils, adjustable in three dimensions

Inspired by the appendages of the America's Cup foiling monohulls, these Y-shaped foils have a wingspan of over 5 metres. They are designed to generate powerful lift, increase power and offer a wide range of adjustments to optimise flight at every point of sail and in all conditions. Beyond their impressive size, these foils feature many unique innovations.

Revolutionary U-shaped rudders

These are probably the most visually striking innovations on the new Maxi Edmond de Rothschild. To fly high above rough seas while maintaining control, the team wanted very long rudders that would remain in contact with the water. The challenge is that longer rudders tend to flex under load, severely affecting steering and the efficiency of their lifting surfaces. A new geometry was needed to give these appendages maximum stiffness, resist cavitation and ultimately improve control of the boat and make better use of its power. The result is a set of U-shaped rudders over 4 metres long, a metre longer than those on Gitana 17. Their shape, reminiscent of a tripod or an inverted π, is only the visible part of what makes them so distinctive.

A daggerboard optimised to stabilise the boat and limit cavitation

With its wide span, the daggerboard resembles an aircraft tail assembly, with two adjustable flaps: one on the vertical section and the other on the horizontal section, the distinctive “manta-ray wing”. On Gitana 18, the innovation is to position this wing behind the vertical part of the appendage, rather than directly beneath it, to minimise flow disturbance and cavitation.

Rig: adjustable spreaders to control mainsail power while sailing

Gitana 18’s mast is 1.50 metres taller than its predecessor’s. The boom is also shorter, creating a more slender sail plan. The major innovation is a set of spreaders that can be adjusted while sailing to bend the mast fore and aft. Actuated by hydraulic rams, these spreaders can pivot through 35 degrees to adjust the bend in the middle of the mast. This unprecedented system allows the sailor to control mainsail power: adding depth in light winds to take off sooner, or flattening the sail to reduce power at high speed or in strong winds. Adjusting the depth, and therefore the power, of the mainsail can also save a solo sailor time and energy by reducing the need for risky manoeuvres or headsail changes.

Central hull:
an integrated, structural coachroof

The naval architects and Gitana design team wanted an exceptionally stiff, structurally robust platform. This applies both to the floats, which must withstand heavy loads from the foils and rudders, and to the central hull, which is subject to torsion. The enclosed coachroof is integrated into the hull and contributes to its structural strength. Inside, the cockpit brings all sail-handling controls together, with ergonomics shaped by many hours of design and development. The coachroof also stands out for the number and size of its windows. This configuration meets the visibility requirements of the Ultim class rules and gives sailors the best possible view to keep a visual watch.

02.02.2008

Lemaire as watchdog.

par Gitana

Saturday, 4:00 UT. We have been playing a new game for the past few hours and expect it to take a few more: jockeying for the best possible timing through Lemaire Channel, which is the door to Cape Horn. For now, looking at the weather reports and latest info from Sylvain Mondon, it’s a no-go. The door is closed! So we tacked and are slowly working our way toward the coast in order to seek some shelter from the wind and sea. The door should open in a few hours, but the crossing from Atlantic to Pacific waters will not be easy. That’s not really news…our marching papers had said the following: the Route de l’Or, rounding Cape Horn against the wind and current. We can’t say that we weren’t forewarned.

Like always, the seas are more of a problem than the wind. This strait between Staten Island and the continent can be compared to the famous Raz Blanchard and the Straits of Bonifacio. Venturi effect, current, it’s all there. But here around the Horn, with its well deserved legend, the air is heavier and denser than anywhere else. The seas are higher and more violent. Six- to 15-meter swells and breaking waves are commonplace here. We’ll have to get used to them if we hope to continue our long voyage.

Last night, we had a brutal reminder of what it’s like to sail upwind in rough seas on a maxi-catamaran. It’s not fun! It’s rough and harsh, not enjoyable. With a steady 45 knots and three reefs, we have adopted a docile sail configuration in order to keep down our speed on a really choppy sea. We have experienced some steep drops where we see Gitana 13’s hulls leave the water all the way to the centerboard before they tip forward into the void and come down with their full force on the water exploding under their weight. The problem here is not trying to go fast, but rather to tame Gitana 13’s power. The boat could certainly bolt across these rough seas, but would inevitably sail off course. The job of the helmsman—who is wearing a drysuit and gloves due to the biting air—is more demanding than ever, as a tiny change in trajectory could affect the boat speed by a factor of two. At 10 knots, okay, but at 20…

Life inside the boat is punishing, since the smallest movement must be calculated and controlled to be successful…even staying in the bunk requires a certain expertise. The crew on deck is rewarded by the surrounding spectacle. We have just experienced our first real gale since the start, but it was against the backdrop of a blue sky. It was beautiful, really, really beautiful.

Goodnight

Nicolas Raynaud

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